How to make procedural Powder Coat material?
You could probably accomplish this pretty easily with a Noise Texture. I just scaled it to 60 and upped the detail and roughness a bit. I mixed it with white before running through a Bump Node to make the effect less jarring, and mixed the main color with an Ambient Occlusion Node to highlight the dimples. I also increased the metallic value to try and make it match the image you posted. Don't forget to enable Ambient Occlusion in the render properties panel: